From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Engine idling, low-speed roughness, and an unsuccessful cold start test on a Bentley III system.
| Identifier | ExFiles\Box 122\4\ scan0205 | |
| Date | 31th October 1938 | |
| -4- Rm{William Robotham - Chief Engineer}/GR.{George Ratcliffe}3/JH.31.10.38. (2) Idling is not quite so consistently good as with the Stromberg carburetter. (3) The engine is rather rougher at bottom speeds than with a standard Wraith system. .......... An attempt was made to start in the cold chamber at 6°F.{Mr Friese} with the Bentley III system. This was unsuccessful owing to the fact that insufficient mixture was being supplied by the starter carburetter to keep the engine running. With this device a very rich mixture is supplied before the engine fires, weakening off as soon as the depression in the induction pipe exceeds that due to motoring the engine over on the starter. Hence if the engine does not fire fairly quickly, it becomes swamped with fuel making a start virtually impossible. It should be understood that this was the first attempt at a really cold start with this type of automatic system, and it should not be assumed that the starter carburetter cannot be modified to meet these demands. Rm{William Robotham - Chief Engineer}/G.Ratcliffe. Rm{William Robotham - Chief Engineer}/T.A.Swinden. | ||